Explosively operated gas supplying apparatus

ABSTRACT

Apparatus for supplying pressurized gas including a container having an outlet opening and an open ended tubular section providing a second opening aligned with the outlet, and a valving device for sealing both openings. The valving device comprises a piston which is held in sealing relationship with the outlet by the pressure in the container and a second piston positioned in the tubular section for partially balancing the pressure acting on the fist piston. The second piston carries an explosive charge and a piston surface to be acted upon by the gas generated by the explosive. Detonation of the explosive charge drives the valving device into an open position.

United States Patent Cirillo 1 51 Mar. 28, 1972 [s41 EXPLOSIV ELY OPERATED GAS 3,209,937 10/1965 111m et a1. 137/69 x SUPPLYIN G APPARATUS Primary Examiner-Stanley H. Tollberg [72] lnventor. John Cirillo, Glen Rldge, NJ. A'tomey Darby and Darby [7 3] Assignee: Walter Kldde 81 Company, Inc., Belleville,

NJ. I [57] ABSTRACT [22] Filed: Aug. 21, '1970 Apparatus for supplying pressurized gas including a container having an outlet opening and an open ended tubular section [21 1 Appl' providing a second opening aligned with the outlet, and a valving device for sealing both openings. The valving device com- U.S. r ....222/3 p ises a piston is in sealing relationship [51] Int. Cl ..B 67b 7/02 Outlet by the pressure in the container and a Second Piston [58] Field Of Search ..222/3; 280/150 AB; 1.37/68, i i d i the tubular section f partially balancing the 137/69 9/314 pressure acting on the fist piston. The second piston carries an explosive charge and a piston surface to be acted upon by the [56] References Cited gas generated by the explosive. Detonation of the explosive UNITED STATES PATENTS charge drives the valving device into an open position.

3,197,234 7/1965 Bertrand ..280/ 150 AB 10 Claims, 1 Drawing Figure EXPLOSIVELY OPERATED GAS SUPPLYING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to vehicle safety apparatus, and, more particularly, to apparatus for protecting an occupant of a vehicle during a collision by inflating a bag to restrain and cushion the occupant.

In recent years a great deal of attention has been devoted to safety systems and devices for protecting the occupants of passenger vehicles, particularly automobiles. One type of system which is currently being given serious consideration employs an inflatable bag or envelope which is stored in a deflated condition, usually in front of the occupant (for example under the dashboard of an automobile). When the vehicle experiences very rapid deceleration such that the occupant would be thrown forward (for example against the dash or windshield), gas stored under pressure is automatically released and the bag is inflated to restrain and cushion the occupant.

A system of this type must operate very quickly. The bag must be inflated in milliseconds after a sudden impact if the occupant is to be protected. The systems which have been previously proposed have employed electrically detonated explosive charges for rapidly releasing the stored gas. The explosive charge is connected to an electrical circuit which includes an inertia responsive electrical switch that closes in response to a predetermined rate of deceleration.

The use of such systems employing an explosive charge has been objected to because of the loud report produced when the charge is detonated.

In the prior systems, the charge is used to either shatter the gas container or to shatter a sea] at the outlet of the container. In either case there is unimpeded sound propogation in the direction of the passengers within the vehicle and an explosive charge ofsubstantial power is required.

SUMMARY Accordingly, it is an object of this invention to provide apparatus for supplying pressurized gas incorporating an explosively operated valve which produces minimum sound.

Another object is to provide such apparatus which requires an explosive charge of minimum size.

Another object is to provide such apparatus for use in a vehicle wherein the propogation of the explosive report toward the passengers is impeded.

The foregoing objects are accomplished by providing apparatus wherein the valve mechanism is pressure balanced so that a small pressure bias holds the valve in the closed position and a small explosive charge is provided to overcome this pressure bias and open the valve.

BRIEF DESCRIPTION OF THE DRAWING A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawing wherein:

The single FIGURE of the drawing is a sectional view of apparatus according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, there is shown apparatus for supplying pressurized gas which includes a container and an explosively actuated valve member 1 1 within the container.

The container is generally cylindrical and is provided with a neck 12 at one end defining an outlet opening 14 and a second neck 15 at the other end. The neck 15 is provided with external threads and has a smaller inner diameter than the neck 12. A generally tubular extension member 16 is threaded onto the neck 15 and has an inner diameter larger than that of the neck.

The valve member 11 includes a piston 19 slideably positioned in the outlet 14, a piston member 20 slideably positioned within the neck 15 and the extension member 16, and a rod 21 rigidly connecting the piston 19 and the piston member 20.v

The piston 19 is sealed to the outlet by an O-ring seal 22, and a snap ring 24 is positioned in a groove within the mouth of the outlet to hold the valve member against the pressure within the container.

The piston member 20 has an inner section 25 which is sealed to the inner surface of the neck 15 by an O-ring seal 26. Piston 20 also has an outer section 27 which seals the inner surface of the extension member 16 by an O-ring seal 29. The section 27 is provided with an annular piston surface 30 and carries an electrically detonated explosive squib 31 which is threaded into an axial bore provided therein. A lateral passageway 32 connects the inner end of the squib 31 with the piston surface 30.

The tubular extension member 16 is provided with a flange 34 which extends radially outwardly for mounting the unit and is provided with a flange 35 extending radially inwardly for limiting the motion of the valve member 1 l.

The piston section 25 is of smaller diameter than that of piston section 19 so that the pressure within the container biases the valve member 11 against the snap ring 24 and maintains the container in the sealed condition.

To open the valve and discharge the gas out of neck 12 into the bag, only the differential pressure between the pistons 19 and 25 need be overcome.

For use in the protection of vehicle passengers the container 10 is mounted in front of a passenger with the tubular extension member pointing in the direction of travel of the vehicle and preferably furthest from the vehicle occupant. An inflatable bag (not shown) is attached to the neck 12 to be deployed toward the passenger upon inflation. The squib 31 is electrically connected to an inertia sensing device.

When the vehicle experiences a dangerous change in velocity, the inertia sensing device connects the squib 31 to a source of electrical power. The squib detonates generating high pressure gas which flows through the passageway 32 and acts upon the piston surface 30 driving the valve member 11 to the left. The piston 19 moves out of the outlet and the container l0 discharges its gas into the bag to inflate it.

Since the squib 31 must overcome only the differential pressure acting upon the piston 19, a very small explosive charge is sufficient to operate the apparatus. In addition, the position of the squib at the furthest point from the passenger, adversely effects the propagation of sound toward the passenger.

It can be seen from the foregoing that the present invention provides apparatus, of the explosively operated valve type for supplying pressurized gas, which upon operation produces minimum sound levels.

I claim:

1. Apparatus for rapidly supplying a fluid medium under pressure comprising in combination a container of fluid medium under pressure having an outlet opening, a valve having a first piston sealing said outlet opening and a second piston connected to said first piston, both of said first and second pistons being in communication with said pressurized fluid medium, said first piston having a larger effective area than said second piston to pressure bias said valve toward said outlet, means for limiting the movement of said valve member toward said outlet, and means including an explosive charge for overcoming said pressure bias to open said outlet and discharge the fluid medium from said container.

2. Apparatus as in claim 1 wherein said container has a second opening within which said second piston is located to seal the same.

3. Apparatus as in claim 1 wherein both of said first and second pistons have faces located within the container to be responsive to the pressurized fluid therein.

4. Apparatus as in claim 1 wherein said first and second openings are in alignment.

5. Apparatus as in claim 1 further comprising a substantially straight member for connecting said first and second pistons.

I terior.

6. Apparatus as in claim 1 wherein said second piston includes a first piston section acted upon by the fluid medium within said container and a second piston section sealed from .said first piston section, said explosive charge being positioned to act on said second piston section of said second piston to move said valve member in a direction to move said first piston out of said outlet opening in towards the container in- 7t Apparatus as in claim 6 wherein said explosivecharge is carried on said second piston and said second piston is pro- A vided with passageway means extending from said charge to said second piston section.

' 8. Apparatus as in claim 6 comprising means on said container to engage said second piston to limit its travel upon ac- 

1. Apparatus for rapidly supplying a fluid medium under pressure comprising in combination a container of fluid medium under pressure having an outlet opening, a valve having a first piston sealing said outlet opening and a second piston connected to said first piston, both of said first and second pistons being in communication with said pressurized fluid medium, said first piston having a larger effective area than said second piston to pressure bias said valve toward said outlet, means for limitIng the movement of said valve member toward said outlet, and means including an explosive charge for overcoming said pressure bias to open said outlet and discharge the fluid medium from said container.
 2. Apparatus as in claim 1 wherein said container has a second opening within which said second piston is located to seal the same.
 3. Apparatus as in claim 1 wherein both of said first and second pistons have faces located within the container to be responsive to the pressurized fluid therein.
 4. Apparatus as in claim 1 wherein said first and second openings are in alignment.
 5. Apparatus as in claim 1 further comprising a substantially straight member for connecting said first and second pistons.
 6. Apparatus as in claim 1 wherein said second piston includes a first piston section acted upon by the fluid medium within said container and a second piston section sealed from said first piston section, said explosive charge being positioned to act on said second piston section of said second piston to move said valve member in a direction to move said first piston out of said outlet opening in towards the container interior.
 7. Apparatus as in claim 6 wherein said explosive charge is carried on said second piston and said second piston is provided with passageway means extending from said charge to said second piston section.
 8. Apparatus as in claim 6 comprising means on said container to engage said second piston to limit its travel upon actuation of the explosive charge.
 9. Apparatus as in claim 7 comprising means on said container to engage said second piston to limit its travel upon actuation of the explosive charge.
 10. Apparatus as in claim 6 wherein said container is provided with an internally stepped tubular extension at said second opening having a first inner diameter in sealing relationship with said first piston section of said second piston and a larger second inner diameter in sealing relationship with said second piston section of said second piston. 